Trichothiodystrophy hair shafts display distinct ultrastructural features.

Hair shafts from three trichothiodystrophy (TTD) patients with mutations in the ERCC2 (XPD) gene were examined by transmission electron microscopy. TTD is a rare, recessive disorder with mutations in several genes in the DNA repair/transcription pathway, including ERCC2. Unlike previous studies, the hair shafts were examined after relaxation of their structure by partial disulphide bond reduction in the presence of sodium dodecyl sulphate, permitting improved visualization.

The worldwide clinical trial research response to the COVID-19 pandemic - the first 100 days.

: Never before have clinical trials drawn as much public attention as those testing interventions for COVID-19. We aimed to describe the worldwide COVID-19 clinical research response and its evolution over the first 100 days of the pandemic. Descriptive analysis of planned, ongoing or completed trials by April 9, 2020 testing any intervention to treat or prevent COVID-19, systematically identified in trial registries, preprint servers, and literature databases.